Testing Android Code - Bitwarden Testing Patterns

• Automatically registers MainDispatcherExtension for UnconfinedTestDispatcher
• Provides stateEventFlow() helper for simultaneous StateFlow/EventFlow testing

Pattern:

class ExampleViewModelTest : BaseViewModelTest() {
    private val mockRepository: ExampleRepository = mockk()
    private val savedStateHandle = SavedStateHandle(mapOf(KEY_STATE to INITIAL_STATE))

    @Test
    fun `ButtonClick should fetch data and update state`() = runTest {
        coEvery { mockRepository.fetchData(any()) } returns Result.success("data")

        val viewModel = ExampleViewModel(savedStateHandle, mockRepository)

        viewModel.stateFlow.test {
            assertEquals(INITIAL_STATE, awaitItem())
            viewModel.trySendAction(ExampleAction.ButtonClick)
            assertEquals(INITIAL_STATE.copy(data = "data"), awaitItem())
        }

        coVerify { mockRepository.fetchData(any()) }
    }
}

For complete examples: See references/test-base-classes.md

StateFlow vs EventFlow (Critical Distinction)

For detailed patterns: See references/flow-testing-patterns.md

B. Compose UI Testing Patterns

Base Class: BitwardenComposeTest

Always extend BitwardenComposeTest for Compose screen tests.

Location: app/src/test/kotlin/com/x8bit/bitwarden/ui/platform/base/BitwardenComposeTest.kt

Benefits:

• Pre-configures all Bitwarden managers (FeatureFlags, AuthTab, Biometrics, etc.)
• Wraps content in BitwardenTheme and LocalManagerProvider
• Provides fixed Clock for deterministic time-based tests

Pattern:

class ExampleScreenTest : BitwardenComposeTest() {
    private var haveCalledNavigateBack = false
    private val mutableEventFlow = bufferedMutableSharedFlow<ExampleEvent>()
    private val mutableStateFlow = MutableStateFlow(DEFAULT_STATE)
    private val viewModel = mockk<ExampleViewModel>(relaxed = true) {
        every { eventFlow } returns mutableEventFlow
        every { stateFlow } returns mutableStateFlow
    }

    @Before
    fun setup() {
        setContent {
            ExampleScreen(
                onNavigateBack = { haveCalledNavigateBack = true },
                viewModel = viewModel,
            )
        }
    }

    @Test
    fun `on back click should send BackClick action`() {
        composeTestRule.onNodeWithContentDescription("Back").performClick()
        verify { viewModel.trySendAction(ExampleAction.BackClick) }
    }
}

Note: Use bufferedMutableSharedFlow for event testing in Compose tests. Default replay is 0; pass replay = 1 if needed.

For complete base class details: See references/test-base-classes.md

C. Repository and Service Testing

Service Testing with MockWebServer

Base Class: BaseServiceTest (network/src/testFixtures/)

class ExampleServiceTest : BaseServiceTest() {
    private val api: ExampleApi = retrofit.create()
    private val service = ExampleServiceImpl(api)

    @Test
    fun `getConfig should return success when API succeeds`() = runTest {
        server.enqueue(MockResponse().setBody(EXPECTED_JSON))
        val result = service.getConfig()
        assertEquals(EXPECTED_RESPONSE.asSuccess(), result)
    }
}

Repository Testing Pattern

class ExampleRepositoryTest {
    private val fixedClock: Clock = Clock.fixed(
        Instant.parse("2023-10-27T12:00:00Z"),
        ZoneOffset.UTC,
    )
    private val dispatcherManager = FakeDispatcherManager()
    private val mockDiskSource: ExampleDiskSource = mockk()
    private val mockService: ExampleService = mockk()

    private val repository = ExampleRepositoryImpl(
        clock = fixedClock,
        exampleDiskSource = mockDiskSource,
        exampleService = mockService,
        dispatcherManager = dispatcherManager,
    )

    @Test
    fun `fetchData should return success when service succeeds`() = runTest {
        coEvery { mockService.getData(any()) } returns expectedData.asSuccess()
        val result = repository.fetchData(userId)
        assertTrue(result.isSuccess)
    }
}

Key patterns: Use FakeDispatcherManager, fixed Clock, and .asSuccess() helpers.

D. Test Data Builders

Builder Pattern with Number Parameter

Location: network/src/testFixtures/kotlin/com/bitwarden/network/model/

fun createMockCipher(
    number: Int,
    id: String = "mockId-$number",
    name: String? = "mockName-$number",
    // ... more parameters with defaults
): SyncResponseJson.Cipher

// Usage:
val cipher1 = createMockCipher(number = 1)  // mockId-1, mockName-1
val cipher2 = createMockCipher(number = 2)  // mockId-2, mockName-2
val custom = createMockCipher(number = 3, name = "Custom")

Available Builders (35+):

• Cipher: createMockCipher(), createMockLogin(), createMockCard(), createMockIdentity(), createMockSecureNote(), createMockSshKey(), createMockField(), createMockUri(), createMockFido2Credential(), createMockPasswordHistory(), createMockCipherPermissions()
• Sync: createMockSyncResponse(), createMockFolder(), createMockCollection(), createMockPolicy(), createMockDomains()
• Send: createMockSend(), createMockFile(), createMockText(), createMockSendJsonRequest()
• Profile: createMockProfile(), createMockOrganization(), createMockProvider(), createMockPermissions()
• Attachments: createMockAttachment(), createMockAttachmentJsonRequest(), createMockAttachmentResponse()

See network/src/testFixtures/kotlin/com/bitwarden/network/model/ for full list.

E. Result Type Testing

Locations:

• .asSuccess(), .asFailure(): core/src/main/kotlin/com/bitwarden/core/data/util/ResultExtensions.kt
• assertCoroutineThrows: core/src/testFixtures/kotlin/com/bitwarden/core/data/util/TestHelpers.kt

// Create results
"data".asSuccess()              // Result.success("data")
throwable.asFailure()           // Result.failure<T>(throwable)

// Assertions
assertTrue(result.isSuccess)
assertEquals(expectedValue, result.getOrNull())

F. Test Utilities and Helpers

Fake Implementations

Exception Testing (CRITICAL)

// CORRECT - Call directly, NOT inside runTest
@Test
fun `test exception`() {
    assertCoroutineThrows<IllegalStateException> {
        repository.throwingFunction()
    }
}

Why: runTest catches exceptions and rethrows them, breaking the assertion pattern.

G. Critical Gotchas

Common testing mistakes in Bitwarden. For complete details and examples: See references/critical-gotchas.md

⛔ STOP — @Suppress("MaxLineLength"): Do NOT add this annotation unless the fun declaration line actually exceeds 100 characters. Count the characters first. Do not copy it from nearby tests. Detekt will tell you if it's needed — when in doubt, leave it off.

Core Patterns:

• assertCoroutineThrows + runTest - Never wrap in runTest; call directly
• Static mock cleanup - Always unmockkStatic() in @After
• StateFlow vs EventFlow - StateFlow: awaitItem() first; EventFlow: expectNoEvents() first
• FakeDispatcherManager - Always use instead of real DispatcherManagerImpl
• Coroutine test wrapper - Use runTest { } for all Flow/coroutine tests

Assertion Patterns:

• Complete state assertions - Assert entire state objects, not individual fields
• JUnit over Kotlin - Use assertTrue(), not Kotlin's assert()
• Use Result extensions - Use asSuccess() and asFailure() for Result type assertions

Test Design:

• Fake vs Mock strategy - Use Fakes for happy paths, Mocks for error paths
• DI over static mocking - Extract interfaces (like UuidManager) instead of mockkStatic
• Null stream testing - Test null returns from ContentResolver operations
• bufferedMutableSharedFlow - Use with .onSubscription { emit(state) } in Fakes
• Test factory methods - Accept domain state types, not SavedStateHandle

H. Test File Organization

Directory Structure

module/src/test/kotlin/com/bitwarden/.../
├── ui/*ScreenTest.kt, *ViewModelTest.kt
├── data/repository/*RepositoryTest.kt
└── network/service/*ServiceTest.kt

module/src/testFixtures/kotlin/com/bitwarden/.../
├── util/TestHelpers.kt
├── base/Base*Test.kt
└── model/*Util.kt

Test Constants Placement

Declare test constants as top-level private const val at the bottom of the file, after the class closing brace. Do NOT use companion object for test constants.

Test Naming

• Classes: *Test.kt, *ScreenTest.kt, *ViewModelTest.kt
• Functions: `given state when action should result`

Summary

Key Bitwarden-specific testing patterns:

1. BaseViewModelTest - Automatic dispatcher setup with stateEventFlow() helper
2. BitwardenComposeTest - Pre-configured with all managers and theme
3. BaseServiceTest - MockWebServer setup for network testing
4. Turbine Flow Testing - StateFlow (replay) vs EventFlow (no replay)
5. Test Data Builders - Consistent number: Int parameter pattern
6. Fake Implementations - FakeDispatcherManager, FakeConfigDiskSource
7. Result Type Testing - .asSuccess(), .asFailure()

Always consult: docs/ARCHITECTURE.md and existing test files for reference implementations.

Reference Documentation

For detailed information, see:

• references/test-base-classes.md - Detailed base class documentation and usage patterns
• references/flow-testing-patterns.md - Complete Turbine patterns for StateFlow/EventFlow
• references/critical-gotchas.md - Full anti-pattern reference and debugging tips

Complete Examples:

• examples/viewmodel-test-example.md - Full ViewModel test with StateFlow/EventFlow
• examples/compose-screen-test-example.md - Full Compose screen test
• examples/repository-test-example.md - Full repository test with mocks and fakes